Throttle mechanism for use in train slack control

ABSTRACT

A manually operated locomotive power control throttle constructed in two parts. The engineer can move one part relative to the other for controlling slack between the cars and can move the two parts in unison for controlling the speed of the locomotive with or without effecting the slack.

United States Patent Inventor Raymond N. Nealls l6 Deepdale Drive E., Levittown, Pa. 12056 877,105

Nov. 17, 1969 Nov. 9, 197 1 Appl. No. Filed Patented THROTTLE MECHANISM FOR USE IN TRAIN SLACK CONTROL 3 Claims, 6 Drawing Figs.

11.8. C1 200/157, ZOO/61.86, 246/187 Int. Cl. 1101b 9/06 Field 01 Search... 200/157,

[56] References Cited UNITED STATES PATENTS 954,517 4/1910 Jarvis 246/187 1,113,027 10/1914 Mastrangelo. 246/187 1,208,129 12/1916 Fuller 200/157 1,961,671 6/1934 Le Fevre 200/157 UX 2,945,100 7/1960 Maurice et a1 ZOO/61.88

Primary Examiner-David Smith, Jr. Assistant ExaminerRobert A. Vanderhye Attorney-Frederick .1. Olsson ABSTRACT: A manually operated locomotive power control throttle constructed in two parts. The engineer can movevone part relative to the other for controlling slack between the cars and can move the two parts in unison for controlling the speed of the locomotive with or without effecting the slack.

SHEET 2 BF 4 PATENTED V 9 O o o O O THROTTLE MECHANISM FOR USE IN TRAIN SLACK CONTROL This invention relates to equipment improving the operation of railroad trains particularly in providing for or preventing slack.

The invention contemplates a novel manually operated throttle for use in the locomotive power control system. The throttle is constructed in two parts so that the engineer can move one part relative to the other and thereby prevent slack between the cars. After the slack is taken out or put in, further rotation of the throttle will effect the increase or decrease in power output. In connection with the throttle, I have provided a lockout lever which will permit the engineer to move the throttle normally without effecting control of slack.

The throttle is best described in the environment of a slack control system and the description which follows takes this into account.

The details of the invention are described below in connection with the following drawings'wherein:

FIG. I is an elevational view partially in section showing a piston and cylinder device for slack control;

FIG. 2 is a plan view partially in section showing the locomotive throttle of the invention for use in conjunction with the device of FIG. 1;

FIG. 3 is a diagrammatic view of a train air system;

FIG. 4 is an elevational view showing a slack control valve;

FIG. 5 is a diagrammatic view of a train air system on a car; and

FIG. 6 is a view to FIG. 1 except that certain movable parts of the throttle are shown in difi'erent position.

In FIG. 1, number 10 identifies the coupler device used to couple two railroad cars together. Impact force exerted upon the coupler device 10 causes drawbar piston 11 having enlarged central diameter 14, to move within drawbar cylinder 12. Fluid in drawbar chamber 13 is exhausted through port 15 in drawbar cylinder 12. Fluid under compression flows through hole 16 in gate valve 17 passing drain plug 20 and flow control valve 21 through port 23 into drawbar cylinder chamber 24. Continuing impact force on coupler device 10 moves bar piston 11 until enlarged central diameter 14 passes over and seals port 15 in drawbar cylinder chamber 13 of drawbar cylinder 12. Fluid in drawbar cylinder chamber 13, now completely captured, reacts against enlarged central diameter 14 of drawbar piston 11, terminating any further movement of drawbar piston 11 by absorbing additional force exerted on coupler device 10. Fluid in drawbar cylinder chamber 25, under compression, will escape to drawbar cylinder chamber 13 through slot 26 in drawbar piston l l.

Tension force exerted upon the coupler device 10 causes drawbar piston I1 having enlarged central diameter 14 to move within drawbar cylinder 12. Fluid in drawbar cylinder chamber 24 of drawbar cylinder 12 is exhausted through port 23, passing flow control valve 21, drain plug 20, through hole 16 in gate valve 17, and entering drawbar cylinder chamber 13 of drawbar cylinder 12 through port 15. Continuing tension force in coupler device 10 moves drawbar piston 11 until enlarged central diameter 14 passes over and seals port 23 in drawbar cylinder chamber 24 of drawbar cylinder 12. Fluid in drawbar cylinder chamber 24 of drawbar cylinder 12, now captured, reacts against enlarged central diameter 14 of drawbar piston 11, terminating any further movement of drawbar piston 11, absorbing any additional tension force exerted on coupler device 10.

In FIG. I, the inner wall of drawbar cylinder chamber 25 is fitted with a keyway 28 in which key 27 in drawbar piston 11 rides to maintain a vertical position of coupler device 10 for proper alignment. Coil spring 29 is attached to one end 30 to the base of drawbar cylinder 12 in drawbar cylinder chamber 25, and the other end 31 of the coil spring 29 is recessed into drawbar piston 11, and secured to drawbar piston 11. Coil spring 29 is designed to react as an emergency protective device against internal damage of the drawbar piston 11 or drawbar cylinder 12 should the captured fluid contained in chamber 13, 24, 25 and bypass chamber 18 of drawbar cylinder 12 be insufficient to insure normal fluid absorption of force originating at coupler device 10. Coil spring 29 maintains the neutral position of enlarged central diameter 14 of drawbar piston 11, midway between port 15 and port 23, in drawbar cylinder 12, when drawbar piston 11 is in position of rest.

In FIG. 1, flexible hose 33 is connected to the pneumaticoperating brake system. When pneumatic-operating brake system is placed in applied position, pneumatic pressure travels through flexible hose 33 into pneumatic-cylinder 32, depressing pneumatic piston 34, within pneumatic cylinder 32. Depressed pneumatic piston 34 in turn depresses gate valve 17, moving hole 16 in gate valve 17 out of alignment with bypass chamber 18 in drawbar cylinder 12, and preventing any flow of fluid from drawbar cylinder chamber 13 to drawbar cylinder chamber 24, thus, completely capturing fluid in chamber 13 and chamber 24 of drawbar cylinder 12. Captured fluid in drawbar cylinder chamber 13 and captured fluid in drawbar cylinder chamber 24 prevent, by reactive pressure upon enlarged central diameter 14 of drawbar piston 11, any motion of drawbar piston 11 through impact or tension force received by drawbar piston 11 through coupler device 10. In this way, a rigid coupling is achieved eliminating the possibility of the creation of an impact force, when pneumatic-operating brake system is applied to decelerate the velocity of objects in motion equipped with this invention.

In FIG. 1, drawbar cylinder head 35 is securely bolted to drawbar cylinder 12 and O-ring 36 is located between joined surfaces of the drawbar cylinder head 35 and drawbar cylinder 12 to prevent escape of fluid between these joined surfaces. A sealing washer 37 is located between drawbar cylinder head 35 and drawbar piston 11 to prevent escape of fluid. Also located in drawbar cylinder head 35 is a dirt seal washer 38 to prevent admission of dirt or foreign Objects into chambers of drawbar cylinder 12. A filler plug 39 is located in the top of drawbar cylinder 12 for the purpose of filling chamber members of the drawbar cylinder 12 with fluid. This filler plug 39 is provided with a sealing washer 40 to prevent escape of fluid from the chambers of drawbar cylinder 12. Bypass chamber housing 41 is securely bolted to external face of drawbar cylinder 12 positioned to align bypass chamber 18 with port 15 and port 23 in drawbar cylinder 12. Two grommet-type sealing washers 42 and 43 prevent escape of fluid where this alignment occurs. A flow control valve 21 located in bypass chamber housing 41 to control velocity of the flow of fluid through bypass chamber 18 by reducing the area of bypass chamber 18. Flow control valve 21 is equipped with a position-retaining locknut 44 and sealing washer 45 to prevent escape of fluid from bypass chamber 18 at control valve 21. The drain plug 20 is located in bypass chamber housing 41 to facilitate the drainage of fluid from the chambers l3, 18, 24 and 25 of the invention. A sealing washer I9 prevents escape of fluid through drain plug 20. A compression spring 46 is located in bypass chamber housing 41 at the base of gate valve 17 and is used to return gate valve 17 to an open position when pneumatic pressure is relieved from pneumatic cylinder 32.

Drawbar cylinder 12 is secured to center sill 47 by pin 48, providing drawbar cylinder 12 a radial movement on pin 48.

In FIGS. 2 and 6, there is shown a throttle control arm 49 that rotates upon a shaft 50 within certain limits of rotation which are defined by a quadrant 51. This quadrant 51 is calibrated by numbered notches 53 of the periphery of the quadrant 51. These numbered notches 53 provide a means for measuring the amount of power applied purpose of acceleration. Exerting a pulling force upon this handle segment 52 will cause it to move clockwise along the quadrant 5! within the terminal limits of the quadrant 51. A pushing force in the opposite direction on the handle segment 52 will cause it to travel counterclockwise along the quadrant 51 in the reverse direction which will decrease the motive power and effect a deceleration of the self propelled unit as will be further explained hereinbelow. The control arm 49 is formed in two segments, the handle segment 52 is joined to the hub segment 54 by means of a pin 55 located on the hub segment. The handle Segment 52 is provided with a hole 56 which receives the pin 55 attached to the hub segment 54. A pulling force upon this handle segment 52 will cause it to rotate around the pin 55 but only to such a point where it will be in alignment with the hub segment 54. This restriction is provided to insure that a pulling force will cause an immediate rotation of the control arm 49, and in turn provide immediate acceleration of the selfpropelled unit to occur at any point within the limitations of travel of the control arm 49 in this direction, as defined by the limits of the quadrant 51. When a pushing force is applied to the handle segment 52 to effect a deceleration of the selfpropelled unit, the handle segment 52 will rotate around the pin 55 to a defined limit 57 as clearly shown in FIG. 6; thence, a continued pushing force upon the handle segment 52 will cause the hub segment 54 also to rotate causing a deceleration to occur at any place along the quadrant 51 within the limitation of the quadrant 51.

This rotation of the handle segment 52 around the pin 55 towards a decelerating position will achieve two resultant actions. As the handle segment 52 is rotated toward the decelerating positions, an insulated metal contact plate 58 located in the handle segment 52 is moved against an insulated metal contact shoe 59; energized with a positive charge of DC current. This insulated metal contact shoe 59 has a fixed location in the hub segment 54. Continued rotation of the handle segment 52 causes the insulated metal contact plate 58 to travel against the insulated slack control shoe 60 (see FIG. 6) establishing a circuit through the insulated slack control shoe 60 which feeds this positive charge into an adjacent slack control relay 61, FIG. 3, having a sustained negative charge.

The relay 6], thus energized, will open the exhaust port in a three-way valve 62, FIG. 3, causing decrease of pressure in the slack control line pipe 63, FIG. 3. This reduction of pressure in the slack control line pipe 63, FIG. 3, will cause the slack control valve 64, FIG. 3, hereinafter described in detail, to close a gate valve which functions similarly to the gate valve 17 previously described and shown in FIG. 1, and thereby lock out slack motion of the drawbar piston 11 and thus eliminate any slack motion of this drawbar piston. A continued pushing pressure on the handle segment 52 in the position shown in FIG. 6 will cause motion of the hub segment 54 on its shaft 50 and consequently deceleration. In this manner, the slack control cushioning draft gear, FIG. 1, on the cars and the selfpropelled unit will operate and eliminate all slack movement within slack control cushioning draft gears, prior to any attempted run-in of slack caused by the effect of deceleration. When the desired point of deceleration has been achieved through a reduction of power only, a pulling force exerted upon the handle segment 52 will cause motion of the handle segment 52 around the pin 55 disengaging the insulated metal contact plate 58 from the slack control contact shoe 60 which in turn deenergizes the slack control relay 61 FIG. 3, closing the exhaust port of the three-way valve 62 which in turn causes the pressure in the slack control linepipe 63 and the slack control valve 64, FIG. 3, to be restored to their normal pressure. This in turn as will be hereinafter described restores all slack movement within the slack control cushioning draft gear, FIG. I, which then allows it to hydraulically absorb and cushion all forces exerted upon it.

The continued pulling force exerted upon the handle segment 52 which has now reached its limit of rotation on the pin 55 places the handle segment 52 in straight alignment with the hub segment 54 (see FIG. 2) and additional pulling force exerted upon the handle segment 52 will rotate the control arm 49 on its shaft 50 in the direction of acceleration.

With reference to FIG. 2, the lock lever 66 permits the throttle control arm 49 to be rotated without affecting the slack control. The lock lever 66 extends from one side of the hub segment 54 in an angular position in relation to the handle segment 52. This lock lever 66 is spring-loaded to maintain this angular or disengaged position. By gripping the finger grip of the lock lever 66 and drawing it toward and against the side of the handle segment 52 the spring-loaded lock shaft 67 is depressed into the hub segment 54 and engages the sidewall of the handle segment 52 on one side of a pointed projection 68 preventing any movement of the handle segment 52 around the pin 55. In this lockout position of the lock lever 66, the slack control cushioning draft gear invention, FIG I, cannot be activated until the lock lever 66 is released and the spring lock shaft 67 returns it to a disengaged position.

The lock lever 66 also can be utilized to permit rotation of the throttle control arm 49 while the slack is locked out. A pushing force exerted upon the handle segment 52 in a direction of deceleration will cause it to rotate around the pin 55 to the position shown in FIG. 6 thereby locking out slack. By maintaining this angular position of the handle segment 52 and drawing the finger grip handle of the lock lever 66 toward the handle segment 52 while it remains in the angled position,

the spring-loaded lock shaft 67 engages one side of the pointed projection 68 preventing any movement of the handle segment 52 around the pin 55 on as shown by the dotted lines in FIG. 6. In this lock-in position, the control arm 49 cannot be rotated without affecting the lockout condition of the slack. Until the lock lever 66 is released and the spring-loaded lock shaft 67 returns the lock lever 66 to a disengaged position. A pulling pressure exerted now upon the handle segment 52 will align it with the hub segment 54, the position shown in FIG. 2, and continued pulling will cause entire control arm 49 to rotate and increase acceleration of the self-propelled unit.

A deadman control lever 69 when released will cause the train brakes to be applied and the slack locked out. In FIG. 2 a deadman control lever 69 is hinged on a pin 70 extending through the handle segment 52 adjacent to the pin 55. This deadman control lever 69 is spring-loaded 71 to elevate it form the handle segment 52 to an angular position above the handle segment 52 when a manual pressure is removed, The piston positioning pin 72 extends through one sidewall of the deadman control lever 69 and into a cavity 73 of the segment 52, where it passes through a vertically elongated hole 74 in a piston 75, movable within the cavity 73. This pin 72 continues through the handle segment 52 an through the opposite sidewall of the deadman control lever 69. The left-hand end of the piston 75 is provided with an insulated contact plate 76 which slides on an exposed surface of the handle segment 52 above and clear of the insulated slack control contact plate 58. The deadman control lever 69, when depressed toward the handle segment 52, the position shown in FIGS. 2 and 6 will rotate on the hinge pin 70 causing the piston-positioning pin 72 to travel in an arc. The piston-positioning pin 72 riding in the vertically elongated slot 74 cause the piston 75 with attached insulated contact plate 76 to travel to the right into the cavity 73, breaking the electrical contact between the insulated contact plate 76 and the fixed contact shoe 59. This insulated contact plate 76 of the piston 75 has a radius of curvature on its contacting surface which permits it to make control with this fixed shoe 59 at any position around a radius described by the motion of the handle segment 52 around the pin 55 when the deadman control lever 69 is released and elevated by its spring loading.

As the deadman contact plate piston 75 travels further into the cavity 73, it depresses a compression spring 71 located between one end of the deadman contact piston 75 and the bottom face of the cavity 73. The spring loading of the deadman contact piston 75 will, upon relief of manual pressure upon the deadman control lever 69, elevate this lever by exerting a pressure upon the sliding deadman contact piston 75 causing it to travel to the left out of the cavity 73 forcing the piston control pin 72 to travel in an arc describing a radius of the hinge pin 70, and also forcing the insulated contact plate 76 against the fixed contact shoe S9, and at the same time, forcing the insulated contact plate 76 against the fixed deadman relay contact shoe and also forcing it against the fixed slack control relay shoe 60, thus completing an electrical circuit between the fixed contact shoe 59 and the dead-man relay fixed contact shoe 77 and also completing an electrical circuit between'the fixed contact shoe 59 and the slack control relay fixed contact shoe 60.

In FIGS. 2 and 6, the quadrant 51 around which this control arm 49 traverses is provided with notches 53. The side face of these notches 53 is inclined and all comers are rounded and the notches are so spaced, in relation to one another that they will allow a spring-loaded notch key 78, having a rounded and 79 that will allow it to engage itself within the various notches located around the quadrant 51 in such a manner that a traversing motion performed by the control arm 49 or the handle segment 52 in either direction around the periphery of the quadrant 51 will cause a sequence of disengagement and engagement in a repetitive order of this notch key 78 by its rounded end 79 riding against the inclined side surface of the notches 53, in which it is engaged, which moves the notch key 78 against a notch key compression spring 80. Compression of this spring 80 allows a displacement of the notch key 78 from the notches 53 to occur until the rounded end 79 is aligned with the next adjacent notch 53. The compression spring 80 reacts against a shoulder 81 on the notch key 78, depressing this rounded end 79 into the next adjacent notch. The notch key spring 80 is retained within the cavity 82 by a tubular plug 83 which is threaded and screwed into this cavity 82. A thumb button 84 on one end of the notch key 78 is extended when the rounded end 79 of the notch key 78 is disengaged from the notch 53. The compression spring 80 then exerts a force upon the shoulder 81 positioning the notch key 78 within this next adjacent notch and drawing the thumb button 84 against the tubular threaded plug 83. This movement of the round end 79 of the notch key 78 in and out of the notches 53 will provide a method of measuring by notches the traversing movement of the control arm 49 around the quadrant 51 by numbering each notch beginning with 0, to indicate the off position of the control arm 49 and successively numbering each notch 53 from that point to the extreme opposite end of the quadrant 51.

By exerting a thumb pressure upon the thumb button 84, a disengagement of the notch in which it is positioned will be prevented for the purpose of sustaining a definite desired position of the control arm 49 or a definite position of the handle segment 52 along the periphery of the quadrant 51.

As shown in F IGS. 2 and 6, the deadman relay contact shoe 77, fixed common feed contact shoe 59, and the slack control relay contact shoe 60 are formed with a curved contact end to facilitate a more complete individual contact between these shoes and the insulated metal contact plates 58 and 76. The insulated metal contact shoes 59, 60, and 77 are all formed with a shoulder 85 at the top and bottom of each shoe, which secures then within an insulated housing 86 which is fonned with parallel vertical oblong openings through which the contact shoes 59, 60, and 77 protrude to the limit of the shoulder 85 of each individual shoe. Each contact shoe 59, 60, and 77 is spring-loaded spring 87 to retain this positioning and provide a flexibility of the contact shoe to ensure a more definite contact with a minimum of friction. Each of the three contact shoes 59, 60, and 77 are formed with a round shaft 88 extending from a posterior surface of the contact shoes 59, 60, and 77 and extends through he compression springs 87 of each shoe and then through an individual round opening 89 in the removable back plate 90 of the insulated housing 86. This back plate 90 is formed to provide sufficient bearing surface in each individual round opening 89 for each shaft 88. At the exposed end of each shaft is a metal contact clamp 88A which provides a means for attaching an insulated electrical wire as shown in the schematic drawing, FIG. 3.

Another and preferred type of gate valve is shown in detail in FIG. 4. In FIG. 4 the preferred gate valve is contained within the slack control valve generally designated 64 and is operated in the manner set forth below. The position of the pans of the valve of FIG. 4 is for the condition of maintaining slack between the cars. The piston 91 moves within a cylinder 92 to an open or closed position. In the slack lockout condition. closed position, the piston 91 is moved to seal off the ports 93 and 94 to prevent flow of fluid through the piston 91. To allow for slack the ports 93 and 94 of the piston 91 open into a cavity 95. The cavity '95 has a central diameter larger than the diameter of the cavity 95 at its ports 93 and 94. A sphere 96 having a diameter greater than the diameter of the ports 93 and 94, but less than the central diameter of the cavity 95 is freely retained within this cavity 95 and will seat itself in one or the other ports 93 and 94 as dictated by the direction of the flow of the fluid through this cavity. The sphere 96 has grooves 97 formed into its surface in an interlaced pattern. The grooves are open at their intersections. The grooves 97 are provided to allow the fluid to flow by when the flowing fluid seats the sphere in either port 93 or 9. The grooves 97 in permitting flow of fluid act like the hole 16 (FIG. 1) in permitting flow of fluid. The piston 91 is provided with electric wipers 98 and 99 and is formed as a hollow cylindrical container 100. Two sets of identical semicylindrical inserts 101 and 102 form the cavity 95. The cylindrical plug 103 is inserted into the hollow cylindrical container and a locking pin 104 is inserted in a hole in the wall of the hollow cylindrical container 100 passing through the cylindrical plug 103 and engaging in a hole in the opposite wall of the hollow cylindrical container 100. This assembled piston 91 is then screwed on to the threaded end of the piston rod 105 that has been passed through the plate 106 and the static seal of 107 of this plate 106. The piston 91 is then inserted into the cylinder 92 after the compression spring 146 has been placed in the base of the cylinder 92. The piston 91 is then in position where it in tersects with the bypass chamber and the ports 93 and 94 are secured in alignment and open to these bypass chambers. An O-ring 108 is located between the external surface of the bypass chamber housing 149 and one external surface of the plate 106 as a seal.

The threaded end of the piston rod 105, to which the piston 91 is attached, extends out of the pneumatic slack control valve housing 109. This housing 109 is positioned against the other external surface of the plate 106 with an O-ring 110 positioned between these surface as a seal. Threaded bolts 111 and 112 pass through a flange on the pneumatic slack control valve housing 109 and through the plate 106, and are screwed into the bypass chamber housing 149 to complete the assembly of the slack control valve 64.

The piston rod 105 passes through a static seal 113 located in the slack control valve housing 109 and through a piston 114 having an elastic wiper 115 in the throttle slack control cylinder 116 and continues through an elastic wiper 117 in the slack control valve housing 109, then into a piston 118 having an elastic wiper 119 in the brake slack control cylinder 120.

Pressurized air released from the brake control valve, FIGS. 3 and 5, enters the slack control valve through brake port 121, FIG. 4,.and continues to the brake slack control cylinder 120 exerting a pressure upon the piston 118, moving the piston connecting rod 105 which closes the piston 91.

Brake control valve, FIGS. 3 and 5, in exhaust position will relieve this air pressure upon the piston 118 and allow compression spring 146 to return cylinder 91 to an open position. Pressurized air from the throttle slack control pipe, FIGS. 3 and 5, enters the slack control valve 64 at throttle port 122 to the reservoir control cylinder 123 moving the reservoir control piston 124 and its connecting rod which in turn moves slide valve 125 and positions the exhaust port 126 of the slide valve 125 to allow air pressure in throttle slack control cylinder 116 to be exhausted allowing compression spring 146 to place cylinder 91 in open position. Displaced reservoir control piston 124 now allows pressurized air to enter a slack control valve reservoir 127 until the pressure of the air inthe reservoir 127 is equal to the pressure of the air entering the throttle port 122. When this air pressure at the throttle port 122 is reduced by energizing the slack control relay, FIG. 3, connected to the throttle control arm 49, FIG. 2, by a movement of the handle segment 52, pressurized air escapes from the reservoir 127 through the reservoir control cylinder 123 and will move the reservoir control piston 124 to a seated and sealed position.

The slide valve 125 connected to the piston 124 by its rod now is moved by this motion of the piston 124 to a position that will allow remaining pressurized air in the slack control valve reservoir 127 to enter the throttle slack control cylinder 116 and move the piston 114 in this cylinder 116, and the piston connecting rod 105 closes the cylinder 91. When the throttle slack control relay, FIG. 3, is again deenergized by a movement of the handle segment 52 and air pressure in the throttle slack control pipe is restored to its normal pressure, air again enters throttle port 122 and continues to the reservoir control cylinder 123 displacing and unseating the reservoir control piston 124 which through its connecting rod moves the slide valve 125 again to an exhaust position to allow air pressure in throttle slack control cylinder 116 to be exhausted allowing the compression spring cylinder 91 to be in open position. Displaced reservoir control piston 124 now allows pressurized air to enter slack control valve reservoir 127 until the pressure of the air in the reservoir is equal to the pressure of the air entering the throttle port 122.

lclaim:

1. A locomotive throttle arm comprising:

a rotatable shaft adapted to be connected to means on the locomotive for controlling the power of the same; a hub connected to said shaft from rotating the shaft; a manually movable handle, the hub and the handle extending generally radially of the rotational axis of said shaft;

pivot means connecting said handle to said hub to provide for rotation of the handle relative to the hub in a direction clockwise to one position and for rotation counterclockwise to another position;

abutment means on said hub defining said rotational positions of said handle with respect to said hub and when the handle is in either of said positions further rotation of the handle in a direction the same as the direction which caused the handle to assume the position effecting a unitary rotation or the handle and whereby to rotate said shaft;

a locking lever extending generally parallel to said handle;

pivot means mounting the locking lever on said hub for motion towards and away from said handle;

spring means biasing said lever to a position spaced from said handle; and

a locking shaft connected with said locking lever and mounted on said hub from movement towards and away from said handle, rotation of the lever towards said handle causing the locking shaft to engage said handle to prevent rotation of the handle with respect to the hub and provide for unitary rotation of the handle and hub whereby to rotate said shaft.

2. A locomotive throttle control arm comprising:

a rotatable shaft adapted to be connected to means on the locomotive for controlling the power output of the same;

a hub connected to said shaft for rotating the shaft;

a manually movable handle, the hub and the handle extending generally radially of the rotational axis of said shaft; pivot means connecting said handle to said hub to provide for rotation of the handle relative to the hub in a direction clockwise to one position and for rotation counterclockwise to another position;

abutment means on said hub defining said rotational positions of said handle with respect to said hub;

a contact plate on said handle adapted to move with the handle above said piston means; and

a pair of contact shoes fixedly mounted on said hub and spaced from one another along an arc whose center lies in the pivot axis so that rotation of said handle with respect to the hub to said one position will cause said contact plate to simultaneously engage said shoes and establish an electrical circuit between the shoes and rotation of the handle with respect to the hub to saidother position will break said engagement.

3. A construction in accordance with claim 3 further includa manually operated deadman control lever;

piston mechanism connecting the deadman control lever with said handle for rotation towards and away from the handle, the lever being normally manually held against said handle;

a piston mounted on said handle for reciprocating motion back and forth in a direction transverse the axis of rotation of the deadman lever, the piston being formed with a slot extending transverse its axis of motion spring means connected between said handle and said piston;

a piston positioning pin connected with said deadman lever and rotatable therewith and extending through said slot, movement of the deadman lever towards said handle causing the pin to engage and move the piston in a direction to compress said spring and the relieving of manual pressure on the deadman lever permitting the spring to cause the piston to engage the pin and move the same in a direction out of said slot and thereby rotate the deadman lever away from the handle;

a contact plate on said piston for movement therewith; and

a contact shoe on said hub adjacent said pair of contact shoes, the piston when moved by the spring causing the contact plate to engage all of said shoes. 

1. A locomotive throttle arm comprising: a rotatable shaft adapted to be connected to means on the locomotive for controlling the power of the same; a hub connected to said shaft for rotating the shaft; a manually movable handle, the hub and the handle extending generally radially of the rotational axis of said shaft; pivot means connecting said handle to said hub to provide for rotation of the handle relative to the hub in a direction clockwise to one position and for rotation counterclockwise to another position; abutment means on said hub defining said rotational positions of said handle with respect to said hub and when the handle is in either of said positions further rotation of the handle in a direction the same as the direction which caused the handle to assume the position effecting a unitary rotation of the handle and hub whereby to rotate said shaft; a locking lever extending generally parallel to said handle; pivot means mounting the locking lever on said hub for motion towards and away from said handle; spring means biasing said lever to a position spaced from said handle; and a locking shaft connected with said locking lever and mounted on said hub for movement towards and away from said handle, rotation of the lever towards said handle causing the locking shaft to engage said handle to prevent rotation of the handle with respect to the hub and provide for unitary rotation of the handle and hub whereby to rotate said shaft.
 2. A locomotive throttle control arm comprising: a rotatable shaft adapted to be connected to means on the locomotive for controlling the power output of the same; a hub connected to said shaft for rotating the shaft; a manually movable handle, the hub and the handle extending generally radially of the rotational axis of said shaft; pivot means connecting said handle to said hub to provide for rotation of the handle relative to the hub in a direction clockwise to one position and for rotation counterclockwise to another position; abutment means on said hub defining said rotational positions of said handle with respect to said hub; a contact plate on said handle and adapted to move with the handle about said piston means; and a pair of contact shoes fixedly mounted on said hub and spaced from one another along an arc whose center lies in the pivot axis so that rotation of said handle with respect to the hub to said one position will cause said contact plate to simultaneously engage said shoes and establish an electrical circuit between the shoes and rotation of the handle with respect to the hub to said other position will break said engagement.
 3. A construction in accordance with claim 3 further including: a manually operated deadman control lever; pivot mechanism connecting the deadman control lever with said handle for rotation towards and away from the handle, the lever being normally manually held against said handle; a piston mounted on said handle for reciprocating motion back and forth in a direction transverse the axis of rotation of the deadman lever, the piston being formed with a slot extending transverse its axis of motion; spring means connected between said handle and said piston; a piston positioning pin connected with said deadman lever and rotatable therewith and extending through said slot, movement of the deadman lever towards said handle causing the pin to engage and move the piston in a direction to compress said spring and the relieving of manual pressure on the deadman lever permitting the spring to cause the piston to engage the pin and move the same in a direction out of said slot and thereby rotate the deadman lever away from the handle; a contact plate on said piston for movement therewith; and a contact shoe on said hub adjacent said pair of contact shoes, the piston when moved by the spring causing The contact plate to engage all of said shoes. 